Plywood Essay, Research Paper
Plywood
Plywood is a sheet of wood that is made from smaller sheets of wood
that are glued together. These sheets of wood are called veneers. Veneers are
normally between 0.09 and 0.32 inches thick. The number of veneers in a
sheet of plywood are usually an odd number. They are usually an odd
number because they are glued together with the wood grain at ninety degree
angles to make the plywood stronger. The two outside faces on a sheet of
plywood are called faces. They are usually of a higher quality veneer. Some
times when thicker panels are being made a piece of regular lumber is used as
the center ply. This type of plywood is called lumber core plywood. Two
types of ply wood are made; interior plywood and exterior plywood. Interior
plywood is used in places where it will stay dry, while exterior plywood can
be used in all types of weather conditions because water proof glues are used.
Plywood is often used for things like making the hulls of small boats or the
floors and ceilings in a house because it can cheaply and easily fill large
spaces.
Plywood has many advantages over regular lumber. It can be made
into large sheets that are stronger than regular lumber of the same thickness.
Plywood does not warp as severely as regular lumber when exposed to the
same weather conditions since the veneers are glued together at ninety degree
angles making it very difficult for the plywood to warp. Plywood can also be
manufactured into its finished product more quickly than regular lumber
because the thin veneers can be dried very quickly.
Various forms of plywood have been made for over 1500 years, but
modern plywood has not been in production for a very long time. Modern
plywood is made by cutting veneer from softwood logs using a rotary lathe.
The first plywood production plant in British Columbia was the Douglas Fir
plant that opened its doors in 1913. Most of the plywood manufactured at
this plant was used for the construction of doors. Two other plywood plants
also opened in British Columbia around that time and they made plywood
mostly from hardwoods. These hardwood plants were opened in New
Westminster and Nelson. But most of the plywood plants opened on the west
coast made plywood from softwood. Softwood plywood was used a lot in
World War Two and became very popular. Soon many plywood mills were
opening in North America to feed the growing demand for plywood. Many
new jobs were created in the new plywood mills and many people were also
employed as loggers to cut down trees for the plywood mills.
The production of plywood is a more difficult one than that of regular
lumber production. A good log is required in order to make high quality
veneers. A good log is called a peeler . A peeler is a straighter and thicker
log than a log that would be used for regular lumber production. Before
modern plywood production thin flat slices from a log were glued together
and no sheets wider than the log itself could be produced. Today we have
better, more modern equipment and synthetic glues that are of a much higher
quality than those produced 1500 years ago. So with our modern technology
we can make far larger sheets and the plastic based glues hold the plywood
together through almost any weather conditions. Some plastic bonded
plywood can be continuously submersed in water without coming apart.
Even stronger plywood is made using heat setting plastic glues. The veneers
are impregnated with the plastic based glues, pressed together and heated.
The veneers unite to for a material that is stronger per pound of weight than
steel. Curved surfaces sheets of plywood can be made in almost the same
way by impregnating the veneers with the glue and pressing them together in
a shaped mold and heating it up. The wings and fuselages of smaller aircraft
are often made in this way. The body panels of Woody Wagons were
made in this way too. When wings and fuselages of airplanes are made in
this way it is supposedly safer than metal because unlike metal the plywood
will not break when exposed to continuous vibrations and stress. It is also
lighter than metal. Many prefabricated buildings are made almost entirely out
of plywood. Plastic bonded woods are used for the exterior while ordinary
plywood is used for the floors and walls of the house. Sometimes the
cabinets counters and cupboards are all made of plywood too.
Another type of plywood is laminated wood . Laminated wood is
made by gluing two or more strips of wood together with their grains running
roughly in the same direction. A piece of laminated wood is no stronger than
a piece of wood that is the same size or kind, but its strength is distributed
more evenly and is less like to warp from fluctuating temperatures and high
humidity than regular lumber. Laminated wood is often used for either
curved or straight roof beams.
The plywood industry employs a great deal of people in the mill and
out in the bush as loggers, surveyors and forestry officials as well as truck
drivers. When all of the wood is gone off a lot the company that had the
timber license must ensure that the lot the timber was taken from is reforested
which also employs the people who replant the lot.
Although there are a lot of people who complain about the amount of
timber harvested, and rightly so, if this timber is replanted as harvested there
should never be a short supply of trees to make plywood out of. These
people have a right to complain if the forestry practices code is violated but if
the code is not violated they should not complain because their house most
likely contains wood or wood products. Some of their friends of family
members also probably have a job in the forestry industry. If the forestry
industry was shut down many people would be out of work and living on the
streets. Also houses and especially other larger buildings would become
much more expensive to build because instead of plywood and other wood
products houses and other building would need to be made of brick
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